In the United States alone, there are 400,000 sudden cardiac deaths annually resulting from cardiac electrical dysfunction. The availability of a non-invasive means of mapping spatially distributed cardiac electrical activity will play a significant role in predicting cardiac dysfunctions and guiding therapeutic techniques. This project aims at greatly enhancing spatial resolution for non-invasive mapping of cardiac electrical activity currently achieved. We have developed a novel imaging technique which has been demonstrated to provide high resolution in mapping cardiac electrical activity. We propose to systematically investigate the relationship between distributed cardiac electrical activity and body surface Laplacian maps when realistic torso geometry is considered. The intensive computation requires the use of supercomputing facilities. We hope this starter grant, if approved, will enable us to explore the feasibility of using the PSC supercomputer to achieve the aforementioned scientific goals, and help make this important imaging technology available to patients suffered from risks of sudden cardiac deaths. No other active or pending supercomputing proposals for this project.